TM 1-1500-204-23-3 (g)    Apply   a   second   coat   of   adhesive (item  18,  table  2-11)  to  buffed  areas  of  patch  and  cell innerliner  and  allow  to  dry  until  tacky.    Adhesive  can become   tacky   within   2   to   4   minutes,   depending   on ambient  temperature  and  humidity.    Perform  knuckle test. NOTE If adhesive dry times are exceeded,    reapplication    of    one coat   of   adhesive   may   be   done only once (total of three coats).  If dry time is again exceeded, remove    adhesive    from    applied area using, acetone and/or buffing with emery cloth (120 grit minimum). (h)    If  necessary  to  restore  tack  of  the cemented surfaces, use a piece of cheesecloth (item 16, table 2-11) dampened with acetone (item 3, table 2-11) and lightly wipe over cemented areas.  Allow solvent to evaporate  10  to  20  seconds  or  until  cemented  areas become "tacky." Wear gloves (item 4, table 2-11). (i)    While  adhesive  is  still  tacky,  apply patch to cemented area of the cell innerliner, centering patch over hole.  With a one-inch, or smaller roller (item 20, table 2-11), roll the patch to the cemented area and roll  it  down  a  1/2  inch  to  1  inch  across  at  a  time  so  as not to trap air between patch and innerliner. (j)    For a hole penetrating the entire cell wall, follow steps (a) through (g) above for application of an  external  patch,  except  use  fabric  (item  25,  table  2- 11) patch material. (k)    Place   a   10   to   25   pound   force   by damping (C-damp (item 21, table 2-11) and two pieces of wood (item 22, table 2-11)), shot bag (item 23, table 2-11),  etc.,  if  practical  on  repair.    Polyethylene,  waxed paper  (item  24,  table  2-11)  should  be  placed  between the patch and force applying device to prevent sticking of the force applying device to the repair. (I) Allow  repair  to  remain  undisturbed for at least 8 hours.  The fuel cell should not be returned to   service   for   24   hours   after   a   cold   patch   has   been applied,  which  is  the  time  required  for  the  adhesive  to become fully cured, at a temperature between 60 ° F to 80° F. (m)    Visually inspect repair for workmanship,  no  loose  edges,  no  voids  and  adhesive fully cured.  If there is a defect in repair, recement per above procedure. (7) Repair/Reattachment of Internal and External Support Hangers/Loops. Repair or reattachment of internal and external support hangers/loops shall be performed as follows: WARNING Acetone  and  repair  adhesives  are flammable  and  toxic.    Keep  away from heat, sparks and open flame. Wear  safety  glasses,  gloves  and protective     clothing     to     prevent contact.  Wear a NIOSH approved air-purifying respirator for organic vapors and work in a well ventilated area.  If contact occurs, flush   areas   with   water   and   get medical   attention.      If   ingestion occurs   get   medical   attention   at once. (a)    Clean  all  bonding  surfaces  using  a piece    of    dean    cheesecloth    (item    16,    table    2-11) dampened   with   acetone   (item   3,   table   2-11).      Wear gloves (item 4, table 2-11). (b)    Lightly   hand   buff   surfaces   to   be bonded with emery cloth (120 grit) (item 17, table 2-11). (c)    Clean buffed areas using a piece of dean  cheesecloth  (item  16,  table  2-11)  dampened  with acetone (item 3, table 2-11).  Wear gloves (item 4, table 2-11).  Allow cleaned areas to dry. WARNING Repair adhesive is flammable and should be kept away from any ignition source. NOTE Adhesive materials should be kept tightly sealed in individual containers in a cool, dry place. (d)    Refer     to     paragraph     c(1)(e)     for mixing instructions. (e)    Apply   one   coat   of   adhesive   (item 18,  table  2-11)  to  buffed  surface  of  hanger  and  buffed area of cell, allow to dry 20-60 minutes. Change 2  2-64